Курить NTP/SNTP.

Часовой пояс для Москвы к примеру:
clock timezone MSK 3
clock summer-time MSD recurring last Sun Mar 2:00 last Sun Oct 3:00

Чтобы дата отображалась в логе и дебуге:
service timestamps log datetime localtime show-timezone msec
service timestamps debug datetime localtime show-timezone msec

>Доброго дня уважаемые :) Подскажите пожалуста как на Catalyst 2950 выставить текущуую
>дату и время.
>Спасибо огромное за помощь

пример:
clock set 13:32:00 23 July 2001

текущая дата:
show clock

Setting the System Clock
If you have an outside source on the network that provides time services, such as an NTP server, you do
not need to manually set the system clock.
Beginning in privileged EXEC mode, follow these steps to set the system clock:
This example shows how to manually set the system clock to 1:32 p.m. on July 23, 2001:
Switch# clock set 13:32:00 23 July 2001
Command Purpose
Step 1 clock set hh:mm:ss day month year
or
clock set hh:mm:ss month day year
Manually set the system clock using one of these formats.
• For hh:mm:ss, specify the time in hours (24-hour format), minutes,
and seconds. The time specified is relative to the configured time
zone.
• For day, specify the day by date in the month.
• For month, specify the month by name.
• For year, specify the year (no abbreviation).